I'm building some solar learning kits for kids, for some outreach events my company has gotten involved in, and what I've got so far is pretty simple, and pretty effective; two 6 V solar panels and one 4x AA holder for power sources, and the devices to drive are a group of 5 LED's, a 12 V fan, and a 5-12 V buzzer. To connect the power sources to the devices, I've got everything ring-terminaled and bolted to a board, from which the kids can use wires with alligator clips to attach to the bolts.
I'll get some pics when my new boxes are complete
But, I want to get a new fan. The one I have is 12 V, and only runs in one direction. I'd like something that will fire up at a lower voltage, and will operate safely (and at different speeds, to illustrate changing voltage) in a 5-12 V range, and that can run in both directions (this will illustrate polarity). The buzzer is great as it will fire up at low voltages (~3V), and gets louder as you increase the power.
Anyone know of anything on the market like that?